| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an electric power steering device which can execute either control of a steering wheel return control or a steering wheel astringency control depending on vehicle speed and steering angular speed even if the device is identically steered, and also can quickly return the steering wheel to a neutral position. SOLUTION: In an electric power steering device where a target value of current of a steering effort auxiliary motor is determined based on steering torque, and the motor is rotated so as to be driven by means of PWM control in such a way that the current of the motor agrees with the target value, the device is provided with a means keeping the device changeable from a condition capable of controlling the steering wheel to be returned to the middle point of a steering angle when the vehicle speed is lower than the third vehicle speed of 20 km/h lower than the first vehicle speed of 30 km/h, to a condition capable of keeping the device controllable continuously when the vehicle speed is between the third vehicle speed of 20 km/h and the first vehicle speed of 30 km/h, and with a means keeping the device changeable from a condition incapable of returning the steering wheel back to the middle point of a steering angle when the vehicle speed is higher than the first vehicle speed of 30 km/h, and when a steering angular speed is greater than the first angular speed of 60 deg./s, to a condition incapable continuously of keeping the device controllable when the vehicle speed is between the first vehicle speed of 30 km/h and the second vehicle speed of 20 km/h.</p> |
